Nixon is always depicted as a villain. Not really something that would take balls to do.

It's more surprising he Isn't the villain

Longshot speculation here but maybe they are twisting the assassination plot of
original story by having it in original timeline Trask and Stryker conspired to have nixon killed and frame mutants for it,and get government support for devolping sentinles.

There has to be something major they are trying to prevent through time travel.
And the way Peter Dinklage describes Trask this Is a possibilty.

Plus when Bryan Singer adapts story from comics he has tendecy to take things and twist them a bit like In X2 turning stryker Into military officer andhaving Xavier tricked through hallunication to wipe out mutants telepathicly.In COmics Strker had military background when young and there was an attempt to brainwash Xavier.

Nixon is always depicted as a villain. Not really something that would take balls to do.

Well it could just be that we're defining "villain" a bit differently here. I think there's a fair chance Nixon will be an antagonist in some sense: he'll probably be condoning whatever high jinks Stryker is up (Trask too) -- at least to an extent. And yeah we might get a little hint of his corrupt paranoid bigotry -- we SHOULD get a hint of that, because Nixon certainly would have been the type to go on bigoted rants about mutants in his secret tapes.

But Fox has always played things cautiously when it comes to the office of the president in X-Men movies. The president has never been depicted as vehemently anti-mutant, and even Senator Kelley was ultimately de-villainized in X1. (This is also consistent with how Marvel usually whitewashes the President). Keep in mind that this is meant to be a family friendly movie: making the President a/the villain is a questioning of authority that's probably too controversial, or, at least, a controversy that's not worth risking. I think he'll be watered down.

Longshot speculation here but maybe they are twisting the assassination plot of
original story by having it in original timeline Trask and Stryker conspired to have nixon killed and frame mutants for it,and get government support for devolping sentinles.

I think it's too similar to X2. I love me some X2 but I hope it's less predictable than this.

"I wouldn't go so far as Hitler," Peter Dinklage told Empire Magazine in a recent interview when asked whether that real life dictator is a good comparison to the fictional X-Men: Days of Future Past villain, Bolivar Trask.

"I sympathise with the man, having played him, and I don't know how one does that with Hitler...Trask does actually believe that what he's doing is going to save the world."

However, the comparison to the Nazi leader is one that director Bryan Singer relates to, especially after the opening scene of X-Men an comparisons between the plight of the Jews and mutants in those two movies.

"Trask is, ultimately, a peace lover. He feels that humanity will go on fighting each other unless they find some common element to unite against. Perhaps as Hitler used the Jews as a scapegoat to bond the darker parts of Europe, he's doing the same thing with mutants."

As for how Dinklage's size factors into his casting, Singer added: "I'm a huge fan of his. But there's also something interesting about his size. I'm sure he went very underestimated throughout life. Trask comments on that - I don't know if it'll be in the final picture - but he says, 'I was underestimated, so do not underestimate these creatures.'"

That's a statement echoed by Dinklage, and it's here that the comparisons to Hitler once again come into play. As it turns out, Trask's size will definitely come into play in the movie.

"I am this guy who's four and a half feet tall, but my life doesn't constantly address it. With me playing that role, I had to think about that stuff. I'm not going to play my violin, but with my dwarfism, I'm a bit of a mutant. I can't move metal or anything, but I thought of it as self-loathing. Deep down, Trask can be quite sensitive about that aspect of himself. And sorry to go back to Hitler, but he wasn't a six foot, perfect blond Aryan. He was a short, funny looking fellow. And talk about a moustache!"

"Trask's agenda is that he's very good at what he does," Dinklage said. "He sees humanity threatened and he has the ability to protect. So that's what he chooses to do." Fans of 'Thrones' should expect Dinklage to provide the mustachioed roboticist with a Tyrion-esque wit. "I can't help but bring a certain amount of levity to things, even when I shouldn't. It's a little dry and one note if you don't have a wink or half-smile. He's very egotistical. He amuses himself."